Polygraph expert zeroes in on Texas Tech scientist

Sunday, March 26, 2006

Tuesday, March 28, 2006
Plain Dealer Science Writer

Previously: On Jan. 14, 2003, the FBI arrived at the laboratory of Texas Tech University researcher Dr. Thomas Butler to investigate the disappearance of 30 vials of plague bacteria. Butler cooperated as the agents questioned him about the threat the missing vials posed. The FBI sent a polygraph examiner to verify the scientist's story.

Before FBI Agent Dale Green had unpacked his lie-detector machine, before he had even met Tom Butler, the man he had flown to Lubbock in the middle of the night to question, Green had decided the scientist wasn't telling the truth.

There was a lot riding on Green's instincts.

The FBI was running a massive investigation, presuming that the 30 vials of plague bacteria Butler had reported missing from his Texas Tech University lab could be in the hands of a bioterrorist.

An attack could be looming anywhere, possibly in President Bush's home state.

Senior law enforcement and homeland security officials were tracking the developments by the hour.

Butler had been advising the lawmen about the threat the missing samples posed.

But there were no obvious signs of a break-in, and after interviewing Butler for a couple of hours, some of the agents had begun to think he was a little too calm for what seemed to them like a crisis situation.

That's where Green came in.

The 25-year FBI veteran assigned to the Dallas field office was about as ambitious an agent as you'd find, a real hard-charger.

Polygraph export zeroes in on scientist

Green held advanced degrees in business and law and was pursuing a third, in forensic psychology. He was an attorney licensed to practice in three states. And since 1997, he'd been certified by the FBI to question people using lie-detection equipment, accurately called a polygraph.

Officially, the FBI considered Butler a crime victim. Since he was the sole source of information in an extremely high-profile case, the bureau wanted to confirm that what he was telling agents about the missing plague was the truth.

Green's boss called him at home around 7 p.m. Tuesday, saying he was urgently needed in Lubbock. His wife drove him to the airport, and an agent delivered Green's polygraph machine, a Lafayette Thermal model in a reinforced case about the size of a laptop bag, but nearly twice as heavy.

He caught the last flight out.

FBI agent scrutinizes Butler's laboratory notes

The FBI had set up a command post at the Lubbock police station. Green arrived at 11:15 p.m.

Supervisory Resident Agent Miles Burden, who'd been coordinating the investigation between Lubbock and Washington, gave Green a quick briefing. Butler was across town at Texas Tech's Health Sciences Center, showing a squad of lawmen his lab. Agents from the bureau's elite Hazardous Materials Response Unit had scoured the place, even poking aside ceiling tiles to make sure no one had hidden the missing vials there as a prank.

While Butler was out, Green had a few minutes to scan the final pages of the scientist's lab notebook, the one in which he had jotted details of his discovery that weekend that the plague vials were gone.

After a more thorough search of his lab Sunday, Butler wrote: “Recheck missing tubes in Set 5. Looked around. Can't explain, other than intentional removal. Suspect theft.”

Green didn't fancy himself an expert in writing analysis, but he'd had some training, and he thought he was on to something.

In previous entries, Butler had written in terse, sterile scientific jargon – just quick bullets of information. The two weekend notations were different, the agent thought. Their style was more narrative, more emotional. There was even an exclamation mark. It was like the author was trying to convince a reader of something, rather than simply recording observations.

Someone else might have thought that Butler was simply affected by excitement or concern when he wrote the passages. To Green, though, what he was reading was clearly a red flag.

He hadn't yet encountered Butler face to face, but already he was certain the scientist had something to hide.

Body language influences agent

They met shortly after midnight, in a tiny interrogation cubicle on the second floor of the Lubbock police department, just down the hall from the detectives' bullpen. An ancient burnt orange carpet covered the floor, and overhead, a pair of fluorescent bulbs spilled chilly white light into the room. A table and two chairs took up most of the space.

On one wall was what looked like a mirror, but was really one-way glass, so that anyone in the darkened anteroom next door could watch. Drawn blinds covered it, blocking the view.

“Hello, I'm Dale Green with the FBI,” the agent said, closing the door behind him and pulling his chair to within a social distance of Butler's. He wore a suit and tie, but wasn't carrying the bureau's standard-issue Glock pistol, which might intimidate his subject.

Green switched off the microphone that would have piped the interview to a speaker in the observation room, but the agents who came and went during the next two hours still could hear snatches of the conversation. FBI policy prohibits agents from recording polygraph sessions.

Wires snaked from the polygraph machine that sat on the table between the two men.

Green explained that he needed to verify what Butler had told agents earlier about the missing plague. Butler could refuse the entire polygraph exam, or reject individual questions. He also had the right to remain silent, and to have a lawyer with him – the standard Miranda advisory.

The scientist was eager to cooperate. He figured he was on the government's side, since he'd been working with federal agencies and the Army all along on his plague research. He had also voluntarily reported the plague vials missing.

To Green, it seemed that Butler was enjoying the limelight.

The agent started with what polygraphers called the pretest interview – a series of questions, from Butler's Social Security number and where he had grown up to details about his plague work.

The queries seemed harmless, and Butler wasn't hooked up to the box yet, but Green had already begun his observations and he believed he was seeing a significant behavioral change.

When Green posed the innocuous background questions, Butler was amiable, chatty. But on the “hot” questions involving plague, the agent saw Butler avert his eyes and cross his arms and legs – telltale “closed” body language.

Asked how dangerous the missing plague bacteria was, the scientist delivered his response about quick, easy weaponization in a monotone, without the anxiety Green thought he should be feeling, especially with his family here in Lubbock.

To the FBI agent, the warning flags were piling up. Though Butler didn't realize it, he was no longer a victim. He was a suspect.